The present invention is directed to a tear strip opening feature for containers, and more particularly to a container including a continuous sealing tape provided with a novel and improved form of tear strip opening device. In its most advantageous form, the sealing tape is utilized to secure a pair of container closing flaps in enclosed and sealed condition and is provided with a novel tear strip feature whereby the container may be quickly and easily opened, providing a clean, neat tear along the severed edges of the tape. If desired, the tape may be provided with perforated punch lines or other lines of weakness along the edges of the tear strip to facilitate easy removal of the tear strip for opening the container.
In one form of the present invention, a container is provided with a continuous sealing tape, which is applied externally of the container, straddling and bridging the space between hinged cover flaps forming a wall (usually the top) of the container. Typically, both of the flaps are hinged, although in certain constructions there may be only a single hinged flap which cooperates with a fixed wall of the container.
In its most elementary form, the sealing tape structure comprises a continuous strip of tearable tape, formed of paper, plastic or like material, which is provided on one surface with an adhesive coating. A reinforcing strip is bonded to the center area of the tape by means of the adhesive coating or by other suitable means and forms a tear band. The bottom surface of the sealing tape structure is adhesively coated over its full surface, except for the exposed surface of the tear band. Perforations or other lines of weakness are formed in the sealing tape, along the edges of the tear band. In order to open the container, the tear band is gripped at one end and pulled upwardly. The body of the tape, being formed of a suitable paper, cloth, plastic or other material which has a tear strength considerably less than that of the underlying tear band, easily tears away to release the container flap. The tape, which is adhesively secured to the closing flaps of the container along its full length, to regions immediately adjacent to the side edges of the reinforcing strip, severs neatly along the boundary between the reinforcing strip and the adhesive bond to the container flaps, providing a neat, clean opening as the tear strip is removed.
In a modified form of the invention, a sealing tape structure includes spaced-apart reinforcing guide strips disposed closely adjacent to and on each side of the central strip, which forms the tear band. All three of the reinforcing strips are bonded by adhesive, heat sealing or other means to the tearable sealing tape. The respective guide strips are in most cases secured to the bottom surface of the sealing tape and are provided with adhesive coatings along their bottom surfaces. Accordingly, when the tearable sealing tape is applied to the closed container, the spaced-apart guide strips are adhesively bonded to the container flaps or walls, in some cases along with the lateral margins of the tape itself. The central reinforcing tear band element is free of adhesive along its bottom surface and bridges the gap between adjacent walls or flaps of the closed container.
In certain advantageous modifications of the invention, reinforcing guide strips of very narrow width are provided along each side edge of the central reinforcing tear band. These narrow guide strips are bonded to the bottom surface of the tearable tape, along with the central reinforcing strip, and adhesive coated margins of the tearable tape extend along side the narrow guide strips at each side. When the sealing strip structure is applied to a container, the narrow guide strips may, but need not necessarily be adhesively bonded to the respective flaps being closed and sealed by the tape. In either case, when the central reinforcing tear band is removed, a neat, clean tear, along the area between the central tear strip and the narrow guide strips.
In a still further modification of the invention, a length of tearable tape bridges over the gap between container flaps and seals them in a closed position. A single reinforcing band, constituting a tear ban,, is adhered centrally to the bottom surface of the tape and bridges over the gap area between the closure flaps. Immediately adjacent to the side edges of the tear band, and extending longitudinally along the tape, are lines of weakness, formed in the tape, as by mechanically weakening the tape and/or heat treating the plastic material thereof, to facilitate tearing along neat, straight lines, when the tear band is removed.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments of the invention and to the accompanying drawing.